Why do you think that over time there are changes in how living things are classified

In my opinion, there are two main reasons why the way we classify living things changes over time:

- The new discoveries of new species: As we started to explore more and more about the world, we also found a lot of new species like new plants or animals, even fossils can help! Let me take an example: at first, people didn't think that dinosaurs and birds are the same species, but thanks to the discovery of Archaeopteryx, we had started to think that there might be some link between these two very different species. As archeologists compare the skeleton of Archaeopteryx and the skeletons of modern bird and dinosaur, they noticed that Archaeopteryx share  some similarites with bothe species. With futher reserch, they finally disvocered that dinosaurs are actually birds ancestors, and they are pratically the same species.

- The way we look at living organism also changed over time: for example, whales were once be mistaken and classified as a fish. But when scientists have genetic information as well as more insight in to their anatomy and behaviours, scientists started to realize that whales and many fish species have a lot of differents despite the fact that they look pretty much alike. For example, pretty much all kinds of fish lay eggs, but whales (and dolphins as well) do something very different, whales give birth to calves, and the newborn animals are capable of swimming right after birth, instead of laying eggs. Base on many more traits, whales were finally classfied as mammal - the same family with gorilla, hippopotamus, etc - instead of fish.

*P/S: I hope this help you

meiosis is the correct answer

question#1

ans:

cell is the basic unit of organization of all living things. cells are often called the building block of life and it is the smallest unit of life. the study of cell is called cell biology. cell consists of cytoplasm enclosed within membrane, which contain bio-molecules such as proteins and nucleic acid.

two third of cell is water, which means that two-third of your whole body is water. the rest is the mixture of molecules, mainly proteins, lipids and carbohydrates.

question#2

ans:

organ:

an organ is a group of tissues specialized to form a functional unit. an example is the heart in animals.

organ system:

an organ system is a group of several organs whose functions are synchronized to release an effective action in a living organism. an example is digestive system.

question#3

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#4

different systems perform different function at tissue level. for example, the respiratory system facilitates breathing. in the alveoli tissue of the lungs, the exchange of oxygen and carbon dioxide molecules between the air and the bloodstream occurs by passive transport, so that oxygen is taken in and carbon dioxide and water are removed. different systems of the body carry out different functions. for example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system is responsible for taking up oxygen and getting rid of carbon dioxide.

question#5

our body works because of the interactions that happen between organs and organ systems.  

for example:  

the heart to regulate blood flow throughout the body. the blood carries oxygen and nutrients to the cells and carries carbon dioxide and waste away from the cells. body systems work together in maintaining a constant internal environment. when this balance is disrupted, the body systems may not function properly, and human health can suffer.   you start to feel bad.